The release of ethylene within plant tissue is by now known to effect a wide variety of responses, such as increased ripening, fruit abscission, increased growth rate, yield, etc.
One compound known to be capable of causing the release of ethylene in a wide variety of plants is 2-chloroethylphosphonic acid. See U.S. Pat. No. 3,879,188. The compound is, however, both expensive and phytotoxic when used at the elevated concentrations sometimes needed.